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b=np2Qg1OgEt3WN2MkvhLzhwY8UbvPQFLhzjnwDrKCU8Kn62aAROgNpcfLruLLIFqp9 IAUL+1FxC8YHK1/fZzgVsHelhu/opytSHJgcIN+O8CD7IktoVyTXP8Gi7/xIp/S1q3 zGORtXd+I/acbf57qO5HQLDXDcvIvXKCf9FZKX45ThMjKe9XBNb3PiuDrRNAMuu710 8zu86r369RHIlhs8R0B+730jKoHmVkdqOKD+Q4dbNv3Xt1bALxSzLY0+rz2TgwMVNz zoISlzkM3+pyKFBoEkeT5wnTdQ0mNdSLGezpn9lPGnEvXgMld3rJogD2+dF+fFRlaC DTtiFvTKOBU+A== From: Pratyush Yadav To: Mike Rapoport , Pasha Tatashin , Pratyush Yadav , Alexander Graf , Muchun Song , Oscar Salvador , David Hildenbrand , Andrew Morton , Jason Miu Cc: kexec@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH 03/12] kho: add a struct for radix callbacks Date: Wed, 29 Apr 2026 15:39:05 +0200 Message-ID: <20260429133928.850721-4-pratyush@kernel.org> X-Mailer: git-send-email 2.54.0.545.g6539524ca2-goog In-Reply-To: <20260429133928.850721-1-pratyush@kernel.org> References: <20260429133928.850721-1-pratyush@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspam-User: X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 7274F40006 X-Stat-Signature: doc3esfzqsfgo1jrdcpc9jwhzdfhw6ei X-HE-Tag: 1777469992-898643 X-HE-Meta: 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 3tSbxKaG mKWhRq+h7/O6qqlFQx3QiZ9w35xPyV8B9DLwXIZzcSZTIa2PXqads2bLVnGbvUo13q1lGw++I5pSWzJ1agL1++U96bre/PaJh7VZSs3LeWfxA3M4RlADVObBj+wXPO0kqPSn0/f3lkDy+R1vEWq93HG1wSE0uBRbUfSxMtxkdJHIkTaxVTgMcCbbYO0eGVraSETWt Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: From: "Pratyush Yadav (Google)" A future commit will add more callbacks for the KHO radix tree. Add a struct for collecting the callbacks. Signed-off-by: Pratyush Yadav (Google) --- include/linux/kho_radix_tree.h | 15 ++++++++++++--- kernel/liveupdate/kexec_handover.c | 29 ++++++++++++++++------------- 2 files changed, 28 insertions(+), 16 deletions(-) diff --git a/include/linux/kho_radix_tree.h b/include/linux/kho_radix_tree.h index f368f3b9f923..030da6399d28 100644 --- a/include/linux/kho_radix_tree.h +++ b/include/linux/kho_radix_tree.h @@ -34,14 +34,23 @@ struct kho_radix_tree { struct mutex lock; /* protects the tree's structure and root pointer */ }; -typedef int (*kho_radix_tree_walk_callback_t)(unsigned long key); +/** + * struct kho_radix_walk_cb - Callbacks for KHO radix tree walk. + * @key: Called on each present key in the radix tree. + * + * For each callback, a return value of 0 continues the walk and a non-zero + * return value is directly returned to the caller. + */ +struct kho_radix_walk_cb { + int (*key)(unsigned long key); +}; #ifdef CONFIG_KEXEC_HANDOVER int kho_radix_add_key(struct kho_radix_tree *tree, unsigned long key); void kho_radix_del_key(struct kho_radix_tree *tree, unsigned long key); int kho_radix_walk_tree(struct kho_radix_tree *tree, - kho_radix_tree_walk_callback_t cb); + const struct kho_radix_walk_cb *cb); #else /* #ifdef CONFIG_KEXEC_HANDOVER */ @@ -54,7 +63,7 @@ static inline void kho_radix_del_key(struct kho_radix_tree *tree, unsigned long key) { } static inline int kho_radix_walk_tree(struct kho_radix_tree *tree, - kho_radix_tree_walk_callback_t cb) + const struct kho_radix_walk_cb *cb) { return -EOPNOTSUPP; } diff --git a/kernel/liveupdate/kexec_handover.c b/kernel/liveupdate/kexec_handover.c index 5758dc6fab5d..4a5d1b47799c 100644 --- a/kernel/liveupdate/kexec_handover.c +++ b/kernel/liveupdate/kexec_handover.c @@ -266,16 +266,18 @@ void kho_radix_del_key(struct kho_radix_tree *tree, unsigned long key) } EXPORT_SYMBOL_GPL(kho_radix_del_key); -static int kho_radix_walk_leaf(struct kho_radix_leaf *leaf, - unsigned long key, - kho_radix_tree_walk_callback_t cb) +static int kho_radix_walk_leaf(struct kho_radix_leaf *leaf, unsigned long key, + const struct kho_radix_walk_cb *cb) { unsigned long *bitmap = (unsigned long *)leaf; unsigned int i; int err; + if (!cb->key) + return 0; + for_each_set_bit(i, bitmap, PAGE_SIZE * BITS_PER_BYTE) { - err = cb(key | i); + err = cb->key(key | i); if (err) return err; } @@ -285,7 +287,7 @@ static int kho_radix_walk_leaf(struct kho_radix_leaf *leaf, static int __kho_radix_walk_tree(struct kho_radix_node *root, unsigned int level, unsigned long start, - kho_radix_tree_walk_callback_t cb) + const struct kho_radix_walk_cb *cb) { struct kho_radix_node *node; struct kho_radix_leaf *leaf; @@ -325,18 +327,16 @@ static int __kho_radix_walk_tree(struct kho_radix_node *root, /** * kho_radix_walk_tree - Traverses the radix tree and calls a callback for each key. * @tree: A pointer to the KHO radix tree to walk. - * @cb: A callback function of type kho_radix_tree_walk_callback_t that will be - * invoked for each key in the tree. + * @cb: Set of callbacks to be invoked during the tree walk. * - * This function walks the radix tree, searching from the specified top level - * down to the lowest level (level 0). For each key found, it invokes the - * provided callback. + * This function walks the radix tree, searching from the top level down to the + * lowest level (level 0), invoking the appropriate callbacks. * * Return: 0 if the walk completed the specified tree, or the non-zero return * value from the callback that stopped the walk. */ int kho_radix_walk_tree(struct kho_radix_tree *tree, - kho_radix_tree_walk_callback_t cb) + const struct kho_radix_walk_cb *cb) { if (WARN_ON_ONCE(!tree->root)) return -EINVAL; @@ -1374,10 +1374,13 @@ EXPORT_SYMBOL_GPL(kho_retrieve_subtree); static int __init kho_mem_retrieve(const void *fdt) { + const struct kho_radix_walk_cb cb = { + .key = kho_preserved_memory_reserve, + }; + kho_in.radix_tree.root = phys_to_virt(kho_get_mem_map_phys(fdt)); mutex_init(&kho_in.radix_tree.lock); - return kho_radix_walk_tree(&kho_in.radix_tree, - kho_preserved_memory_reserve); + return kho_radix_walk_tree(&kho_in.radix_tree, &cb); } static __init int kho_out_fdt_setup(void) -- 2.54.0.545.g6539524ca2-goog